Waving and straightening human hair with 1,4-dimercapto-2,3-butane diol and substituted products thereof



United States Patent O WAVING AND STRAIGHTENING HUMAN HAIR WITH 1,4-DIMERCAPTO-2,3-BUTANE DIOI. AND SUBSTITUTED PRQDUCTS THEREOF John C. Zemlin, Reading, and Katherine A. Herrington, Brookline, Mass., assignors to Collaborative Research, Incorporated, Waltham, Mass. No Drawing. Filed Mar. 10, 1966, Ser. No. 533,236

Int. 'Cl. A4511 7/04 US. Cl. 132-7 7 Claims ABSTRACT OF THE DISCLOSURE A method of treating hair is provided with the improvement comprising exposing the hair to a swelling agent and then contacting the hair with a solution of 1,4 dimercapto-2,3 butane diol or asubstituted product thereof; to reduce disulfide linkages in the hair.

The present invention relates to hair treatment and more particularly to a method and means for straightening or curling hair.

In recent times it has been common to curl womens hair both at home and in commercial establishments by a cold waving method. Hair is composed of keratin which comprises long chain molecules cross linked together by disulfide bonds. In the cold waving method, the disulfide bonds are reduced and broken at room temperature by a reducing agent whereupon the hair strands can be reshaped as on curlers. Ina subsequent step sulfhydryl groups, which have been formed by reduction of disulfide bonds in the hair molecules, are oxidized to reform the disulfide bonds again and cross-link molecules together in different molecular orientations. The hair strands so treated tend to conform to the shape of the curlers about which they are wound during the oxidizing step.

Most commercial cold Waving preparations employ derivatives of thioglycolic acid as a reducing agent for breaking the bonds between sulfur atoms and consequently the molecular chains. Various inorganic and amine salts of thioglycolic acid are commonly employed for this purpose in combination with a standard swelling agent for the hair strands. In general, these materials have limited stability, being quite sensitive to air oxidation. The solid anhydrous salts such as the ammonium salt are particularly unstable and must be very carefully packaged to minimize deterioration. The alkali metal salts are also difiicult to use in hair waving owing to their tendency to be strongly alkaline. Moreover, all of the thioglycolate salts are odoriferous and it is difficult to completely eliminate their vile odor which is highly ob jectionable to many users. Other thiols such as ammonium thiolactate, various salts of ,B-mercaptopropionic acid and the like have similar disadvantages.

An important object of this invention is to provide a means and method for treating hair which means and method is useful in cold waving of hair.

Another important object of this invention is to provide a means and method in accordance with the preceding object which permits dry packaging and storage of a reducing agent.

Still another object of this invention is to provide a means and method in accordance with the preceding objects which is highly eificient employing only a limited quantity of material to effect reduction of disulfide linkages in hair strands.

Still another object of this invention is to provide a means and method in accordance with the preceding objects which is extremely efficient and does not create an oflensive odor during permanent waving or straightening of hair by a cold waving method.

According to the invention 1,4 dimercapto-2,3 butane diol having the formula where A and B are hydroxyl groups is used to reduce disulfide linkages of hair to form sulfhydryl groups which can later be oxidized to reform hair molecules in curled or straightened forms. In the method of this invention hair is exposed to a swelling agent and contacted with a solution of 1,4 dimercapto-2,3 butane diol preferably at room temperature. It has been found that an unexpectedly small quantity of 1,4 dimercapto-2,3 butane diol is highly active to reduce hair as compared with the previously used thiols .and particularly thioglycolates such as ammonium thioglycolate. Either the trans or cis form of the diol can be used. The efficiency of our compound is probably due to the formation of a stable ring compound after reaction with the disulfide linkages whereas ammonium thioglycolate participates in an equilibrium reaction where a substantial excess is required in order to have the reaction proceed.

While 1,4 dimercapto-2,3 butane diol in either of its isomer forms is preferred for use in this invention, one or both of the hydroxyl groups can be removed and substituted with other water soluble polar groups including NH -PO H COOH and SO H. When one of the hydroxyl groups is so substituted, hydrogen may be used for the remaining A or B group although this is not preferred. In some cases either one of the hydroxyl groups can be removed and substituted with hydrogen. Examples of suitable compounds are: (1,4, dimercapto-Z hydroxy-n-butyl) 3-phosphate, (1,4 dimercapto-Z hydroxy-n-butyl) 3-sulfonate, 1,4 dimercapto-2-amino-3hydroxy butane, 1,4 dimercapto-2 hydroxy-3-carboxy butane, (1,4 dimercapto-n-butyl) 3-sulfonate as well as their salts. These materials are solids at room temperature. Thus, they can easily be packaged in convenient dry packages and since they are highly soluble in water or conventional swelling agents for hair, they can easily be dissolved just prior to application in a cold waving procedure.

In a particular method of employing the preferred compound, 1,4 dimercapt0-2,3 butane diol is used as a reducing agent in curling hair, the hair is first washed and then exposed to an aqueous solution of the agent or .a solution of the reactant in a conventional hair swelling agent. The reducing step is allowed to proceed substantially at room temperature preferably for a time within the range of from about 5 to minutes or more depending upon the concentration of the reducing agent which is preferably in the range of a .02 to 1.0 molar aqueous solution. Reduction is carried out preferably while the hair is wrapped or being wrapped about hair curlers or other curling means and as a practical matter the time to wrap the entire head of hair usually determines the reducing time. After this step the hair is washed in water and exposed to a conventional oxidizing agent to reform the disulfide linkages in the hair. In a subsequent step the hair may again be washed to remove the oxidizing agent and is found to conform to the configuration imparted by the curling pins or other means.

The reducing step can be carried out in the presence of any of the known swelling agents such as organic or inorganic bases including potassium hydroxide, sodium hy-' droxide, ammonium hydroxide, monoethanolamine, triethanolamine, morpholine and others. Such materials normally impart a basic pH to the reducing solution in the range of from 9 to 11 and higher. However, in certain cases swelling agents such as urea can be used in conjunction with the reducing agent thereby lowering the pH to a substantially neutral value. Substantially neutral pH values are preferred since there is less likelihood of damage to the hair during the reducing step.

The oxidizing step can be carried out in a conventional manner as is known in cold waving techniques using such known oxidizing agents as sodium perborate, potassium perborate, hydrogen peroxide, sodium bromate and potassium bromate. The oxidizing step is preferably carried out substantially at room temperature for periods of from about minutes to several hours. As is known care must be taken not to overoxidize the hair molecules as this may tend to split hair strands, bleach the hair or make it water labile. In addition, the known air oxidation using trace amounts of metal catalysts can be used.

The following illustrative examples indicate the effectiveness of 1,4 dimercapto -2,3 butane diol in reducing hair as compared with a conventional cold waving preparation. It should be understood that these examples are illustrative only and are in no way limiting.

Example 1 Coarse brunette human hair was selected and shampooed with Halo shampoo and rinsed thoroughly in water. The hair was separated into three swatches numbered l, 2 and 3 which were used in the experiments. Sample 1 was used as a control and was treated only with 0.6 M ammonium hydroxide. Sample 2 was treated with a commercially obtained Toni waving lotion, and sample 3 was treated with 0.2 M 1,4 dimercapto -2,3 butane diol in 0.6 M ammonium hydroxide. The commercial waving lotion was found to contain 0.6 M ammonium thioglycolate in ammonium hydroxide.

Each of the hair swatches was soaked in the reducing solutions for 15 minutes at room temperature, then rinsed under running warm water for 2 minutes.

After the reducing procedure portions of each of the hair swatches of samples 1, 2 and 3 were analyzed for disulfide content using the phosphotungstate procedure.

According to this method, free sulfhydryl residues are alkylated first (in 2% iodoacetic acid in glacial acetic acid) to prevent free cystine from going to disulfide The hair is then dried and hydrolyzed. In the colorimetric assay, cystine is reduced and then reacted with color reagent, sodium tungstate in phosphoric acid, the deep blue color is read at 740 m Concentrations are determined from a standard curve prepared with cystine hydrochloride. (In this procedure total cystine is highest for untreated hair: a decrease in the cystine content of treated hair is expected.)

The table below indicates the results otbained:

CYSTINE DETERMINATION O.D. Total Mg. mole N o. 740 amolcs moles hair mg.

(1) Untreated .455 3.1 31 41.3 0.75 (2) Toni 360 2.36 23.6 50.0 0. 47 (3) DT'I .384 2.6 20 51.8 0.50

Thus it can be seen that about the same degree of reduction of cystine was obtained using either a .6 M thioglycolate solution or a .2 M 1,4 dimercapto -2,3 butane diol.

Example 2 rod, rewetting with reducing solution and letting stand 15 minutes.

Test Composition Final pH A 1,4 dimercapto-2,3 butane diol, 0.2 M; Triton 9.1 X-200 (a Rohm and Hess product which is a wetting agent comprising the sodium salt of polyethoxydiisobutylpheuol sulfonic acid),

3.7% (by wt.); NII4OH, less than 0.05 N. B 1,4 dimercapto-2,3 butane diol, 0.2 M; glyelnc, 9.0 0.4)M; Urea 0.2 M; Triton X-200, 3.7% (by wt. C Ammonium tl1ioglycolate,0.6 M; NHiOH, 0.5

M; Triton X-200, 3.7% (by wt.). 9.1 Super Toni Home Permanent waving lotion. 9. 2 1,4 dimercapto-2,3 butane diol, 0.2 M; glycine, 7.9

0.2 M; urea, 08 M; Triton X-200, 3.7% (by wt.). F 1,4 dimercapto-2,3 butane diol, 0.2 M; glycine, 0.2 M; urea, 0.8 M; NHOI'I, 0.1 N; sodium lauryl sulfate, 0. 1% (by wt.). 8. 5 G Ammonium thioglycolatc, 0.0 M; glycine, 0.5 8.3 M; urea, 0.8 M; sodium lauryl sulfate, 0.1% (by wt).

Afterwards each tress was rinsed with 200 ml. of warm water, toweled and let stand 30 minutes, after wh1ch a commercial neutralizer (a dilute solution of hydrogen peroxide) was poured over the curl. After five minutes the curling rod was removed and more neutralizer poured through the curl. The curl was then rinsed with ml. of warm water, combed, rewrapped on a curling rod and dried in a stream of warm air.

The degree of wave obtained was determined by immersing the dry curl in tap water for five minutes, combing out, reimmersing briefly and suspending vertically for visual examination. The results from the above test were as follows:

Appearance ot Hair It is evident that this 1,4 dimercaptan is effective in the waving of hair at lower pHs than ammonia thioglycolate. It is also effective at lower concentrations than is the case with ammonium thioglycolate where 0.5 M is about the mininum strength ever used to wave hair.

When the OH groups of the 1,4 dimercapto -2,3 butane diol are substituted with other polar, water soluble groups as previously described, in each case a good curl is produced.

A hair waving kit can easily be formed in accordance with this invention employing a package containing a predetermined amount of a dry reducing agent of this invention. Additional dry packages can contain the swelling agent and oxidizing agent. The dry swelling agent can be packed with the dry reducing agent. The amount of each material is predetermined to give sufiicient reducing and oxidizing solutions for a permanent wave when mixed with water or other solvent.

While a specific example showing the method of this inventionhas been described, it should be understood that many variations thereof are possible. For example, curly hair can be treated and later oxidized to straighten it. The particular times, tempertaures and conditions can vary.

What is claimed is:

1. A method of treating hair comprising,

exposing said hair to a swelling agent and,

contacting said hair with an aqueous solution of 1,4

dimercapto -2,3 butane diol to reduce disulfide linkages in said hair,

said solution having a pH in the range of from about 7 to 11 and said 1,4 dimercapto -2,3 butane diol being in a molar concentration of at least 0.02. 2. A method in accordance with the method of claim 1 wherein said swelling agent is selected from the group consisting of inorganic bases, organic bases and urea,

and said 1,4 dimercapto -2,3 butane diol is in a molar concentration of from about 0.02 to 1.0.

3. A method in accordance with the method of claim 1 and further comprising the steps of subsequently oxidizing said hair to reorient molecules of said hair and semi-permanently curl said hair.

4. A method in accordance with the method of claim 3 wherein said oxidizing is carried out substantially at room temperature with a reagent selected from the group consisting of hydrogen peroxide, sodium bromate, potassium bromate, sodium perborate and potassium perborate.

5. A method in accordance with the method of claim 1 wherein at least one of the hydroxyl groups in said 1,4 dimercapto -2,3 butane diol is replaced with a member of the group consisting of hydrogen and a water soluble, polar group.

6. A method in accordance with the method of claim 5 wherein said water soluble, polar group is selected from 6 the group consisting of NH -PO H COOH and SO3H- 7. A method in accordance with the method of claim 1 wherein both of the hydroxyl groups in said 1,4 dimercapto -2,3 butane diol are removed and substituted with hydrogen and a water soluble, polar group.

References Cited UNITED STATES PATENTS 2,577,710 12/1951 McDonough 16787.1 2,577,711 12/1951 McDonough 167-87.

OTHER REFERENCES Chemical Abstracts 43; 7424-7425 (1949).

ALBERT T. MYERS, Primary Examiner VERA C. CLARKE, Assistant Examiner U.S. Cl. X.R. 8-127; 424-71 

